Fuel and lubricant additives

ABSTRACT

Compounds of the general formula I 
     
         Z--CH.sub.2 --NY.sub.2-n H.sub.n                           (I) 
    
     where 
     n is 0 or 1, 
     z is a straight-chain or branched polyalkyl radical having a number average molecular weight of from about 150 to 40,000, and 
     Y is a radical of the formula IIa or IIb ##STR1## where the radicals R, R 1  and R 2  independently of one another, are each hydrogen, an unsubstituted or substituted alkyl, alkenyl or alkynyl radical or an unsubstituted or substituted cycloalkyl, aryl or arylalkyl radical, which may carry one or more heteroatoms, and 
     A is an alkyleneimine radical; or, if 
     n is 0, one of the radicals Y may be a polyoxyalkylene radical, and processes for their preparation and fuel and lubricant compositions, and mixtures of additives, which contain the novel compounds.

The application is a 371 of PCT/EP97/00849, filed Feb. 21, 1997.

The present invention relates to novel derivatized polyalkylamineadditives for fuels and lubricants, processes for the preparation ofthese additives and fuels and lubricants and additive concentrates whichcontain these novel additives.

Carburettors and intake systems of gasoline engines as well as injectionsystem for fuel metering in gasoline and diesel engines are becomingcontaminated with impurities to an increasing ex- tent. The impuritiesare the result of dust particles from the air taken in by the engine,uncombusted hydrocarbon residues from the combustion chamber and thevent gases from the crank case which are passed into the carburettor.

These residues shift the air/fuel ratio during idling and in the lowerpart-load range so that the mixture becomes richer and the combustionmore incomplete. As a result of this, the proportion of uncombusted orpartially combusted hydrocarbons in the exhaust gas and the benzeneconsumption increase.

It is known that these disadvantages can be avoided by using fueladditives for keeping valves and carburettor or intake systems clean(cf. for example: M. Rossenbeck in Katalysatoren, Tenside,Mineraloladditive, Ed. J. Falbe, U. Hasserodt, pp. 223, G. ThiemeVerlag, Stuttgart 1978). Depending on the mode of action and preferredplace of action of such detergent additives, a distinction is now madebetween two generations. The first generation of additives was only ableto prevent the formation of deposits in the intake system, not to removeexisting deposits. On the other hand, additives of the second generationcan prevent and eliminate deposits (keep-clean and clean-up effect).This is permitted in particular by their excellent heat stability inzones of relatively high temperature, in particular in the intakevalves.

The molecular structural principle of these additives of the secondgeneration which act as detergents is based on the linkage of polarstructures to generally relatively high molecular weight, nonpolar oroleophilic radicals. Typical members of the second generation ofadditives are products based on polyisobutene in the nonpolar moiety, inparticular additives of the polyisobutylamine type.

Such detergents can be prepared by two different multistage synthesisprocesses, starting from polyisobutenes.

The first process involves chlorination of the polymeric parentstructure, followed by nucleophilic substitution of the polymeric parentstructure by amines or, preferably, ammonia. The disadvantage of thisprocess is the use of chlorine, which results in the occurrence ofchlorine- or chloride-containing products, which is not at all desirabletoday.

In the second process, the polyisobutylamines are prepared starting frompolyisobutene, by hydroformylation and subsequent reductive aminationaccording to EP 0 244 616.

If ammonia is used in the reductive amination in the second process, thereaction products of the ammonia usually display excellent efficiencywith regard to keeping valves and carburettors clean, but they are atbest neutral in their action on an engine lubricant, in particular withregard to their oil sludge-dispersing actions.

Additives which are particularly advantageous from the technical andeconomic point of view are therefore those which simultaneously combinethe properties of detergents and dispersants and are obtainable bysimple, chlorine-free synthesis processes.

Such additives are disclosed in EP 0 568 873. The latter describesβ-aminonitriles of the formula ##STR2## where R^(a) is an aliphatichydrocarbon radical having alkyl side groups and an average molecularweight of from 250 to 5,000 and R^(b), R^(c) and R^(d), independently ofone another, are each hydrogen or C₁ -C₈ -alkyl or R^(b) and R^(d) areeach phenyl,

and the corresponding N-alkyl-1,3-propylenediamine obtained byhydrogenation.

There is, however, an additional demand for further chlorine-freeadditive components in order to be able better to adapt the additives tothe requirements of the respective application.

It is the object of the present invention to provide further compoundswhich are suitable as fuel and lubricant additives and are obtained bychlorine-free synthesis.

We have found that this object is achieved by providing derivatives oflong-chain amines which are obtained by functionalization of the aminegroup by a cyanomethylation or by reaction with diketenes. For thepurpose of the present invention, cyanomethylation is the linking of acyanoalkyl group by its α-carbon atom to an amine nitrogen.

The present invention relates in particular to compounds of the generalformula I

    Z--CH.sub.2 --NY.sub.2-n H.sub.n                           (I)

where

n is 0 or 1,

Z is a straight-chain or branched polyalkyl radical having an averagemolecular weight of from about 150 to 40,000,

Y is a radical of the formula IIa or IIb ##STR3## where R, R₁ and R₂ areidentical or different and, independently of one another, are selectedfrom the group consisting of hydrogen, unsubstituted and substitutedalkyl, alkenyl and alkynyl radicals and unsubstituted and substitutedcycloalkyl, aryl and arylalkyl radicals which may contain one or moreheteroatoms; and

A is an alkyleneimine radical of the formula III ##STR4## where m is aninteger from 0 to 10;

Alk is straight-chained or branched, unsubstituted or substitutedalkylene;

R³ is hydrogen, alkyl, alkenyl, alkynyl, aryl or, if Y is a radical offormula IIA, a keto radical of the formula IVa ##STR5## where R has theabove mentioned meanings;

or, if Y is a radical of formula IIb, a cyano radical of the formula IVb##STR6## where R¹ and R² have the above-mentioned meanings;

or, if

n is O, one of the radicals Y may be a polyoxyalkylene radical of theformula (V) ##STR7## where q is an integer from 1 to 30,

Alk is as defined above and

E is hydrogen or C₁ -C₆ -alkyl.

According to a first preferred embodiment the present invention relatesto cyanomethylated compounds of the formula I, where Z and n have theabove-mentioned meanings and Y is a radical of the formula IIc ##STR8##where R¹, R², R³ and m have the above-mentioned meanings,

R⁴ and R⁵ are identical or different and have the meanings stated abovefor R¹ and R², and

p is an integer from 2 to 5.

More preferred cyanomethylated additives are compounds of the formula I,where

Z, m, n and p have the above-mentioned meanings,

R¹ and R², independently of one another, are selected from the groupconsisting of hydrogen and alkyl, in particular C₁ -C₁₀ -alkyl,

R³ is hydrogen, alkyl, in particular C₁ -C₁₀ -alkyl, or a cyano radicalof the formula IVb, and

R⁴ and R⁵, independently of one another, are each hydrogen or C₁ -C₆-alkyl.

Particularly preferred additives are those in which Z is a radicalcomposed of isobutene units and having a number average molecular weightof about 800-1500, n is 0 or 1 and Y is a group of the formula

    --CR.sup.1 R.sup.2 --CN

where R¹ and R², independently of one another, are each hydrogen or C₁-C₁₀ -alkyl.

According to another preferred embodiment the present invention relatesin particular to diketene derivatives of the general formula Ia ##STR9##where Z, R and n have the above-mentioned meanings.

The radicals R, independently of one another, are preferably eachhydrogen, a straight-chain or branched, unsubstituted or substituted C₁-C₃₀ -alkyl, C₂ -C₃₀ -alkenyl or C₂ -C₃₀ -alkynyl radical or anunsubstituted or substituted C₃ -C₈ -cycloalkyl, phenyl, naphthyl orphenyl-C₁ -C₁₂ -alkyl or naphthyl-C₁ -C₁₂ -alkyl radical, which maycarry one or more heteroatoms.

Compounds of the formula Ia, where Z has a number average molecularweight of from about 800 to 1500, n is 0 or 1 and radicals R areidentical and selected from hydrogen and C₁ -C₃₀ -alkyl are particularlypreferred.

The polyalkyl radical Z in compounds of the general formula (I) ispreferably obtained by homo- or copolymerization of straight-chain orbranched C₂ -C₃₀ -alkenes, preferably C₂ -C₆ -alkenes, particularlypreferably C₂ -C₄ -alkenes. Particularly preferred C₂ -C₄ -alkenes are1-alkenes, such as propylene, 1-butene and isobutene. For example, Z maybe derived from a copolymer of 1-butene and isobutene, and Z maylikewise have an average molecular weight of from about 800 to about1500.

Alkyl radicals which maybe used according to the invention are straightor branched, saturated hydrocarbon chains of 1 to 30 carbon atoms.Examples are C₁ -C₆ -alkyl, such as methyl, ethyl, n-propyl, iso-propyl,n-butyl, sec-butyl, iso-butyl, tert-butyl, n-pentyl, sec-pentyl,iso-pentyl, n-hexyl or 1-, 2- or 3-methyl-pentyl, long-chain alkylradicals, such as straight-chain heptyl, octyl, nonyl, decyl, undecyl,lauryl, tridecyl, myristyl, pentadecyl, palmityl, heptadecyl, stearyl,nonadecyl, arachinyl, behenyl, lignoceryl, ceryl and myricyl, and thesingularly or multi-ply branched analogues thereof. Preferred long-chainradicals are lauryl, myristyl, palmityl, stearyl and arachinyl.

Alkenyl radicals which may be used according to the invention arestraight or branched hydrocarbon chains having at least onecarbon--carbon double bond and having 2 to 30 carbon atoms. Examples ofmono unsaturated C₂ -C₃₀ -alkenyl radicals are C₂ -C₆ -alkenyl radicalssuch as vinyl, allyl, 1-propenyl, isopropenyl, 1-, 2- or 3-butenyl,methallyl, 1,1-dimethylallyl, 1-, 2-, 3-, 4- or 5-hexenyl, long-chainradicals, such as straight-chain heptenyl, octenyl, nonenyl, decenyl,undecenyl, dodecenyl, tridecenyl, pentadecenyl, palmitoleyl, icosenyland triacontenyl, and the branched analogues thereof, where the doublebond may occur in any desired position. According to the invention, boththe cis and the trans isomers of the above C₂ -C₃₀ -alkenyl radicals areincluded. A preferred mono unsaturated long-chain radical is oleyl.

Alkynyl radicals which may be used according to the invention arestraight or branched hydrocarbon chains having at least onecarbon--carbon triple bond and 2 to 30 carbon atoms. Examples includeethinyl, 1- or 2-propinyl, 1-, 2- or 3-butinyl and the correspondingalkynyl analogues of the above-mentioned alkenyl radicals.

Cycloalkyl radicals which may be used according to the invention includeC₃ -C₈ -cycloalkyl radicals such as cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopropylmethyl,cyclopropylethyl, cyclopropylpropyl, cyclobutylmethyl, cyclobutylethyl,cyclopentylethyl, cyclopentylpropyl and the like.

Examples of aryl radicals which may be used according to the inventionare phenyl and naphthyl.

Arylalkyl radicals which may be used according to the invention are inparticular phenyl-C₁ -C₁₀ -alkyl and naphthyl-C₁ -C₁₀ -alkyl, the C₁-C₁₀ -alkyl moiety being as defined above.

The cycloalkyl, aryl and arylalkyl groups which may be used according tothe invention may, if required, contain 1 or more, for example 1 to 4,heteroatoms, such as 0, S and N, oxygen and nitrogen being preferred asheteroatoms. Examples of cyclic heteroalkyl radicals aretetrahydrofuranyl, piperidinyl, piperazinyl and morpholinyl. Examples ofheteryl groups are 5- or 6-membered aromatic ring systems which comprisefrom 1 to 4 of the stated heteroatoms, eg. furyl, pyrrolyl, imidazolyl,pyrazolyl, oxazolyl, isoxazolyl, oxadiazolyl, tetrazolyl, pyridyl,pyrimidinyl, pyrazinyl, pyradizinyl, triazinyl, tetrazinyl and the like.

Straight-chain or branched alkylene radicals which may be used accordingto the invention include straight-chain C₁ -C₁₀ -alkylene radicals, eg.ethylene, propylene, butylene, pentylene and hexylene, and branched C₁-C₁₀ -alkylene radicals, eg. 1,1-dimethylethylene,1,3-dimethylpropylene, 1-methyl-3-ethyl-propylene, 2,3-dimethylbutylene,1,3-dimethylbutylene, 1,1-dimethylbutylene, 1,2-dimethylpentylene and1,3-dimethylhexylene.

Examples of substituents which are suitable according to the inventionare C₁ -C₆ -alkyl, C₁ -C₆ -alkoxy, C₂ -C₆ -alkenyl, C₁ -C₆ -alkanoyl,such as acetyl and propionyl, nitro and amino.

The present invention furthermore relates to a process for thepreparation of compounds of the general formula (I), wherein apolyalkylamine of the general formula VI ##STR10## where Z has theabove-mentioned meanings,

W is hydrogen or --A--H, and

A is an alkyleneimine radical of the formula VII ##STR11## where Alk andm have the above-mentioned meanings and R⁶ is hydrogen, straight-chainor branched alkyl, alkenyl or alkynyl or aryl, either

a₁) is reacted with at least one diketene of the formula IX ##STR12##where R has the above mentioned meanings, in an inert solvent, in orderto obtain a compound of formular I, where in at least one radical Y isof formula IIa, or

a₂) is reacted with hydrocyanic acid or a salt thereof and least onecompound of the general formula VIII ##STR13## where R¹ and R² have theabove-mentioned meanings in order to obtain a compound of formula Iwherein at least one radical Y is of formula IIb.

The reaction a₂) preferably is carried out in an aqueous medium in thepresence of a phase-transfer catalyst.

If, in the reaction product obtained, according to a₁) or a₂) W ishydrogen, this can, if desired, be substituted in a conventional mannerby a group of the formula V ##STR14## where Alk, E and q have theabove-mentioned meanings.

The derivatization of the polyalkylamines with diketenes according toprocess a₁) to give the novel diketene-derivatized compounds is carriedout in a manner known per se by adding the diketene to thepolyalkylamine in the absence of a solvent or in an inert solvent, whilecooling, at room temperature or at elevated temperatures, depending onthe reactivity of the reactants. Examples of suitable solvents includesulfur- and chlor-ne-free solvents, such as relatively high-boilinghydrocarbons, eg. n-hexane, n-octane, n-decane or isododecane, ordipolar aprotic solvents, such as anhydrous tetrahydrofuran. Thepolyalkylamine is preferably dissolved in a suitable solvent, and thediketene, if necessary dissolved in the same solvent, is added dropwisewhile stirring. The reaction products obtained can be used withoutfurther purification, if necessary after distilling off the solvent orremoving excess reagents.

According to the prior art, the cyanomethylation of amine is usuallycarried out by the "Strecker-Synthesis" (cf. for example: Strecker, Ann.Chem. 75, (1850), 27; Kendall, McKenzie, Org. Synth., 9, (1929), 4; H.Bucherer, A. Grolee, Chem. Ber. 39, (1906), 992; E. Knoevenagel, Chem.Ber. 37, (1904), 402; DE 2 107 757; DE 2 624 891) by reacting the aminewith aqueous formaldehyde and hydrocyanic acid. Reaction ofpolyisobuteneamines of the above formula VI with hydrocyanic acid orsalts of hydrocyanic acid and formaldehyde or paraformaldehyde does notlead to the desired reaction, even with the addition of solubilizers.Surprisingly, however, it was found, according to the invention, thatthe novel cyanomethylated additives can be prepared according to processa₂) in surprisingly good yield by adding a phase-transfer catalyst.

The nucleophilic substitution of halogenated hydrocarbon compounds withsodium cyanide under phase-transfer catalysis is generally known (C. M.Starks, J. A. Chem. Soc. 93, (1971), 195), as is the hydrocyanation ofcarbonyl compounds with the phase-transfer catalysts (C. L. Liotta, A.M. Dabdoub and L. H. Zalkow, Tetrahedron Lett., (1977), 1117). However,the use of phase-transfer catalysts in the cyanomethylation ofhydrophobic amines is novel. It is surprising that the reaction isaccelerated although formaldehyde is added in an aqueous solution.

Suitable phase-transfer catalysts for carrying out the novel process a₂)include quaternary ammonium and phosphonium salts, although quaternaryammonium salts are preferred. Examples of phase-transfer catalysts whichmay be used are benzyltriethyl-ammonium chloride, tetrabutylammoniumbromide, methyltricapryl-ammonium chloride and methyltributylammoniumchloride and the corresponding halogen-free forms of these compounds.

The novel preparation process a₂) is preferably carried out by aprocedure in which the polyalkylamine of the formula VI is dissolved ina suitable solvent, eg. tetrahydrofuran or another dipolar aproticsolvent, and the phase-transfer catalyst is added to the solution. Anaqueous cyanide solution in which the ketone compound of the formulaVIII has been dissolved is then added. The reaction mixture is heated toabout 40-70° C. and the pH of the solution is kept at about 8-9. Afterthe end of the reaction, the organic phase is separated off and thedesired additive is isolated therefrom.

If mixtures of ketone compounds of the general formula VIII are used inthe novel preparation process, the novel additives simultaneouslycontain different terminal cyano groups of the formula IIb.

The polyalkylamines of the general formula VI can be prepared byhydroformylation of reactive polyalkenes and subsequent reductiveamination of the oxo product. The reactive polyalkenes having an averagemolecular weight of from about 150 to 40,000 are homo- or copolymers ofstraight-chain or branched C₂ -C₃₀ -alkenes, preferably C₂ -C₆ -alkenes,in particular C₂ -C₄ -alkenes. Reactive polyalkenes include unsaturatedpolymers of high chemical homogeneity, more than 10% of the double bondsbeing in the alpha position. A possible method for the preparation ofreactive polyalkenes is disclosed in DE 27 02 604. Particularlypreferred reactive polyalkenes are those which are prepared from1-alkenes, in particular propylene, 1-butene, isobutene or mixturesthereof. Other suitable polyalkylamines of the general formula VI areamines according to EP 0 244 616 and EP 0 695 338, the content of whichis hereby incorporated by reference. EP 0 244 616 describes inparticular polyalklamines in which Z is derived from isobutene and up to20% by weight of n-butene, it being possible for the molecular weight ofthe polyisobutene radical to be from about 300 to about 5000. EP 0 695338 describes in particular polyalkylamines in which Z is derived fromone or more 1-n-alkenes of 3 to 6 carbon atoms and up to 50 - % byweight of ethene, it being possible for Z to have about 20-400 carbonatoms.

However, an important criteria for all polyalkylamines which may be usedaccording to the invention is that they contain at least one primary orsecondary amine group which can be derivatized by cyanomethylation or byreaction with diketenes, as described above.

Additives particularly preferred according to the invention are thosewhich are prepared starting from polybutylamines and polyisobutylaminesof the formula VI and which are disclosed in EP 0 35 244 614.

The present invention furthermore relates to lubricant compositionswhich contain at least one novel polyalkylamine derivative according tothe above definition, if necessary in combination with furtherconventional lubricant additives. Examples of conventional additives arecorrosion inhibitors, antiwear additives, viscosity improvers,detergents, antioxidants, antifoams, lubricacy improvers and pour pointimprovers. The novel compounds are usually present in amounts of fromabout 1 to 15, preferably from about 0.5 to 10, % by weight, based onthe total weight of the composition.

Examples of lubricants prepared according to the invention include oilsand greases for motor vehicles and industrially used drive assemblies,in particular engine oils, gear oils and turbine oils.

The present invention furthermore relates to fuel compositions, forexample fuels for gasoline and diesel engines, which contain the noveladditives. The novel compounds serve therein in particular as detergentsfor keeping the fuel intake system clean. Owing to their dispersingproperties, they have an advantageous effect on the engine lubricant,which they can enter during operation.

To test the novel products with regard to their dispersant properties,it is possible to use a spot test, as described, for example by A.Schilling in "Les Huiles pour Moteurs et la Graissage des Moteurs", Vol.1, 1962, page 89 et seq., in a somewhat modified form.

The novel polyalkylamine derivatives are metered into commercial fuelsin a concentration of from about 20 to 5000, preferably from about 50 to1000, mg/kg of fuel. The novel additives can, if required, also be addedtogether with other known additives.

While novel additives in which Z has a number average molecular weightof about 2000-40,000 are preferably used in lubricant compositions,compounds in which Z has a number average molecular weight of about150-5000, preferably about 500-2500, and in particular about 800-1500,are particularly useful for use as fuel additives.

Finally, the present invention relates to additive mixtures which, inconcentrated form, contain at least one novel compound in combinationwith other fuel additives, in particular detergents and dispersants. Acombination with, for example, polyisobutylamines disclosed in U.S. Pat.No. 4,832,702 is particularly preferred.

In principle, any known product from among the products suitable forthis purpose, may be used as a detergent component in the novel additivemixtures, said products being described, for example, in J. Falbe, U.Hasserodt, Katalysatoren, Tenside und Mineraloladditive, G. ThiemeVerlag, Stuttgart, 1978, page 221 et seq., or in K. Owen, Gasoline andDiesel Fuel Additives, John Wiley & Sons 1989, page 23 et seq.

N-containing detergents, for example compounds which contain an amino oramido group, are preferably used. Polyisobutylamines according to EP 0244 616, ethylenediaminetetraacetamides and/orethylenediaminetetraacetimides according to EP 0 188 786 orpolyetheramines according to EP 0 356 725 are particularly suitable, andreference may be made to the definitions in these publications. Owing totheir method of preparation, the products described there likewise havethe advantage of being chlorine- or chloride-free.

On the other hand, these additives may also be combined with carrieroils. In particular, carrier oils based on polyalkylene glycol, forexample corresponding ethers and/or esters, as described in U.S. Pat.No. 5,004,478 or DE 38 38 918 A1, are suitable. Polyoxalkylene-monooleshaving terminal hydrocarbon groups (U.S. Pat. No. 4,877,416) or carrieroils as disclosed in DE 41 42 241 may also be used.

The examples which follow illustrate the present invention.

EXAMPLE 1

Preparation of cyanomethylated polyisobuteneamine

250 g of polyisobuteneamine (M_(w) about 1000) are mixed with 125 g oftetrahydrofuran and 250 g of water, and 55 g of formaldehyde (30%strength) are added. After addition of 0.57 g of benzyltri-ethylammoniumchloride and 81.7 g of 33% strength aqueous sodium cyanide solution, thepH of the aqueous solution is brought to about 9 with 56 g of 50%strength aqueous sulfuric acid. While stirring vigorously, the pH iskept at 8-9 for 2 hours at 60° C. by adding a total of 14 g of 15%strength aqueous sodium hydroxide solution. After this time, theconversion is 89%, based on unconverted cyanide. After cooling, thesupernatant organic phase is separated off and extracted twice byshaking with 300 g of water. After the solvent has been stripped offunder reduced pressure, 244 g of a highly viscose product remain,corresponding to 90% of theory. A mixture of unsubstituted,monosubstituted and disubstituted polyisobuteneamine is obtained, thedetermination being based on NMR and mass spectrometry.

EXAMPLE 2 Comparative Example

a.) 110 g of 30% strength aqueous formaldehyde and 30 g of hydrocyanicacid are added dropwise in succession at 20° C. to a solution of 500 gof polyisobuteneamine in 1.5 1 of tetrahydrofuran. This mixture isstirred for 35 hours at 60° C.; after this time, the conversion is <20%,based on unconverted cyanide. After the organic phase has been separatedoff and the solvent distilled off, only unconverted polyisobuteneamineis obtained.

b.) 15 g of hydrocyanic acid are added dropwise at 20° C. to a solutionof 250 g of polyisobuteneamine in 100 g of tetrahydrofuran, and asolution of 22.5 g of trioxane in 50 g of tetrahydrofuran issubsequently added dropwise in the course of 1 hour at the sametemperature. After a total of 30 hours at 60° C., the solvent isremoved; according to NMR analysis, polyisobuteneamine having a degreeof substitution of <20% remains.

EXAMPLE 3

Reaction of polyisobutylamine (PIBA) with distearyl diketene

An equimolar amount of distearyl diketene (0.4 mol) was added in thecourse of 20 minutes to a solution of 0.4 mol of PIBA (PIBA preparedaccording to EP 0 244 616, MW˜1041) in isododecane at 40° C. Thesolution thus obtained was stirred for a further 30 minutes at 40° C.and then cooled to the room temperature. A colorless liquid wasobtained.

Yield: quantitative IR (Film, cm⁻¹): 3300 (N--H); 2950; 2925; 2845; 1705(C═O); 1630 (O═C--NH--); 1455; 1390; 1350; 1220.

EXAMPLE 4

Reaction of polyisobutylamine with distearyl diketene

0.4 mol of PIBA (PIBA prepared according to EP 0 244 616, MW˜1041) washeated to 60° C. 0.4 mol of distearyl diketene was then slowly added.After the end of the addition, the reaction mixture was stirred for afurther 45 minutes and then cooled to room temperature. A colorless,viscous oil was obtained.

Yield: quantitative IR (Film, cm⁻¹): 3300 (N--H); 2950; 2925; 2845; 1705(C═O); 1630 (O═C--NH--); 1455; 1390; 1350; 1220.

EXAMPLE 5

Reaction of PIBA with dioleyl diketene

A solution of 0.4 mol of PIBA (PIBA prepared according to EP 0 244 616,MW˜1041) in isododecane at 30° C. was initially taken. 0.4 mol ofdioleyl diketene was slowly added dropwise with vigorous stirring. Afterthe end of the addition, the solution was stirred for a further 45minutes. A pale yellow liquid was obtained.

Yield: quantitative IR (Film, cm⁻¹): 3300 (N--H); 2950; 2925; 2845; 1705(C═O); 1630 (O═C--NH--); 1455; 1390; 1350; 1220.

EXAMPLE 6

Reaction of polyisobutylamine (PIBA) with diketene

A solution of 17.6 g (0.21 mol) of diketene in 100 ml of tetrahydrofuranwas added dropwise in the course of one hour to a solution of 207.8 g(0.20 mol) of polyisobutylamine (PIBA prepared according to EP 0 244616, MW˜1041) in 1000 ml of anhydrous tetrahydrofuran at 0° C. whilestirring. The reaction was slightly exothermic. The stirring process wascontinued for a further two hours at 0° C. Thereafter, the solvent wasdistilled off and remaining traces of tetrahydrofuran and diketene wereremolded at 50° C. and 0.5 mbar. 222.0 g (0.197 mol) ofN-acetoacetyl-polyisobutylamine remained behind as a slightly yellowishviscous oil.

Yield: virtually quantitative Amine number: 0 IR (Film, cm⁻¹): 2950,1650, 1470, 1390, 1365, 1230 ¹³ C-NMR (100 MHz, CDCl₃, extract): δ=22.70(q, CH--CH₃), 29.54 (q, H₃ C--C═O), 37.75 (t, CH₂ --CH₂ --N), 49.51 (t,CH₂ --CO--CH₃), 165.11 (HN--C═O), 204.76 (H₃ C--C═O), 31.24 (q), 38.15(s), 59.70 (t) (polyisobutyl). For comparison: ¹³ C-NMR of the PIBA used(100 MHz, CDCl₃, extract): δ=23.06 (CH--CH₃), 26.55 (CH--CH₃), 40.27(CH₂ --NH₂), 44.14 (CH₂ --CH₂ --NH₂); 31.32 (q), 38.17 (s), 59.56 (t)(polyisobutyl).

EXAMPLE 7

Engine test for testing the action as intake system cleaner

Testing the products of the present invention as fuel additives, inparticular with regard to their suitability of the present invention asintake system cleaners, is carried out with the aid of engine testswhich are performed in test bed trials with a 1.2 l Opel Kadett engineaccording to CEC F/04/A/87. Fuel used: European premium-grade unleaded.The results are summarized in table 1 below.

                  TABLE 1                                                         ______________________________________                                        Reduction of deposits in the intake valve                                     Additive  Dose    Intake valve deposits [mg]*                                 from example                                                                            [mg/kg] Valves   1    2     3    4                                  ______________________________________                                        1         200              0    12    0    6                                                             (554)                                                                              (343) (293)                                                                              (484)                              6         200              3    2     2    2                                                             (277)                                                                              (175) (183)                                                                              (337)                              3         200              8    4     3    5                                                             (554)                                                                              (343) (293)                                                                              (484)                              ______________________________________                                         *Values in brackets: Deposits without the addition of an additive        

We claim:
 1. A compound of the formula I

    Z--CH.sub.2 --NY.sub.2-n H.sub.n                           (I)

where n is 0 or 1; z is a straight-chain or branched polyalkyl radicalhaving an average molecular weight of from about 500 to 40,000; Y is aradical of the formula IIa or ##STR15## where each R is identical ordifferent and, is selected from the group consisting of hydrogen,unsubstituted and substituted alky, alkenyl and alkynyl radicals andunsubstituted and substituted cycloalkyl, aryl and arylalkyl radicalswhich optionally contains one or more heteroatoms- and A is analkyleneimine radical of the formula III ##STR16## where m is an integerfrom 0 to 10; Alk is straight-chained or branched, unsubstituted orsubstituted alkylene; R³ is a keto radical of the formula IVa ##STR17##where R has the above-mentioned meanings;or, if n is 0, one of theradicals Y may be a polyoxyalkylene radical of the formula V ##STR18##where q is an integer from 1 to 30, Alk is as defined above and E ishydrogen or C₁ -C₈ -Alkyl.
 2. A compound as claimed in claim 1, of theformula Ia ##STR19## where Z, R and n have the above mentioned meanings.3. A compound as claimed in claim 1, wherein Z and n have the abovementioned meanings and the radicals R, independently of 30 one another,are each hydrogen, a straight-chain or branched, unsubstituted orsubstituted C₁ -C₃₀ -alkyl, C₂ -C₃₀ -alkenyl or C₂ -C₃₀ -alkynyl radicalor an unsubstituted or substituted C₃ -C₈ -cycloalkyl, phenyl, naphthyl,phenyl-C₁ -C₁₂ -alkyl or naphthy-C₁ -C₁₂ -alkyl radical, which may carryone or more heteroatoms.
 4. A compound as claimed in claim 2, wherein zand n have the above mentioned meanings and the radicals R,independently of one another, are each hydrogen, a straight-chain orbranched, unsubstituted or substituted C₁ -C₃₀ -alkyl, C₂ -C₃₀ -alkenylor C₂ -C₃₀ -alkynyl radical or an unsubstituted or substituted C₃ -C₈-cycloalkyl, phenyl, naphthyl, phenyl-C₁ -C₁₂ -alkyl or naphthyl-C₁ -C₁₂-alkyl radical, which may carry one or more heteroatoms.
 5. A compoundas claimed in claim 1, wherein the radicals R have the same meanings andare selected from hydrogen and C₁ -C₃₀ -alkyl.
 6. A compound as claimedin claim 1, wherein Z is a polymer radical derived from at least onestraight-chain or branched C₂ -C₃₀ -alkene, preferably C₂ -C₆ -alkene,in particular C₂ -C₄ -alkene, or a mixture thereof.
 7. A compound asclaimed in claim 6, wherein the alkene is a 1-alkene.
 8. A compound asclaimed in claim 7, wherein the 1-alkene is selected from propylene,1-butene and isobutene.
 9. A compound as claimed in claim 8, wherein Zis derived from polybutene or polyisobutene or a copolymer of isobuteneand up to 20% by weight of n-butene, and has an average molecular weightof from about 800 to about
 1500. 10. A process for the preparation of acompound as claimed in claim 1, whereina) a polyalkylamine of theformula VI ##STR20## where Z has the above-mentioned meanings, W ishydrogen or --A--H, and A is an alkyleneimine radical of the formula VII##STR21## where Alk and m have the above-mentioned meanings and R⁶ ishydrogen, straight-chain or branched alkyl, alkenyl or alkynyl or aryl,is reacted with at least one diketene of the formula IX ##STR22## whereR has the above mentioned meanings, in an inert solvent, in order toobtain a compound of formula I, wherein in at least one radical Y is theformula IIa,and b) if W is hydrogen in the product formed, the hydrogenmay optionally be replaced by a group of the formula V ##STR23## whereAlk, E and q are defined above.
 11. A lubricant composition comprisingone or more compounds as claimed in claim 1, n a total amount of about1-15% by weight, based on the total weight of the composition,optionally in combination with further conventional lubricant additives.12. A lubricant composition as claimed in claim 11, comprising at leastone compound of the formula I, where Z has a number average molecularweight of from about 2000 to 40,000.
 13. A fuel composition comprisingone or more compounds as claimed in claim 1 in a total concentration offrom about 20 to 5000 mg/kg of ruel, optionally in combination withfurther conventional fuel additives.
 14. A fuel composition as claimedin claim 13, comprising at least one compound of the formula I), where Zhas a number average molecular weight of from about 500 to
 2500. 15. Anadditive mixture for fuels or lubricants, comprising one or morecompounds as claimed in claim 1, optionally in combination with furtherconventional additive components.
 16. A compound as in claim 6 whereinthe straight-chain or branched alkene is C₂ -C₈ -alkene or a mixturethereof.
 17. A compound as in claim 16 wherein the straight-chain orbranched alkene is C₂ -C₄ -alkene.